Many portable, hand-held electronic devices are powered by removable and rechargeable battery packs. The battery packs are typically secured in an operable position by a single latching mechanism or by a door assembly that covers and encloses the battery pack. For example, U.S. Pat. No. 3,999,110 discloses a battery pack and latch assembly for use with cordless power tools wherein a single, biased battery latch retains the battery pack and provides a quick disconnect feature that allows a user to remove and replace the rechargeable battery in a very fast and time efficient manner.
As seen in U.S. Pat. No. 5,220,520, battery powered, hand-held computers and bar code scanners also use quick disconnect, single latch systems to retain replaceable, rechargeable battery packs. As such, a user can quickly disconnect and remove the battery and replace it with a fresh battery. These battery retention systems reduce down time of the device while changing batteries.
The drawback to the single latch, battery retention system is the battery pack can be quickly disconnected from the hand-held computer. When the battery pack is suddenly removed from the computer, power to the device is instantly terminated and data stored in the computer's open data directories can be lost, because power to properly close the device's memory storage mechanism is not available. Thus, while the single latch arrangement allows for the quick removal of the power source, it does not give the computer enough time to properly store data captured therein as it shuts down.
A further drawback of the single latch battery retention system is the absence of a backup latching system. When the single latching system fails or is inadvertently released, the battery pack can fall out of the electronic device and be damaged. The inadvertent removal of the battery pack can also cause a sudden and improper shut-down of the device and a loss of data.
Therefore, there is a need for a battery pack latching system that avoids the problems resulting from sudden termination of electrical power to a computer or scanner. In addition, there is a need to avoid inadvertent removal of a battery pack and the resulting damage to the battery pack and loss of data.